Modal Analysis of Generator End Winding Components
Modal analysis of generator end windings can be used before and after generator wedge replacement to assess wedge and blocking tightness.
An accelerometer is attached to each end winding and response measurements are taken with instrumented impact hammer. These measurements yield an estimate of natural frequencies and their associated mode shapes. These measurements are conducted before and after tightening of wedges.
First Natural Frequency
Second Natural Frequency
Third Natural Frequency
Fourth Natural Frequency
Comparison of before to after wedge tightening using clarity of individual natural frequency mode shape and response amplitudes will indicate whether wedging is sufficiently tight.